---
id: OrderItem
name: OrderItem
version: 1.0.0
identifier: orderItemId
summary: Represents a single item within a customer's order.

properties:
  - name: orderItemId
    type: UUID
    required: true
    description: Unique identifier for the order item
  - name: orderId
    type: UUID
    required: true
    description: Identifier for the parent Order
    references: Order
    relationType: hasOne
  - name: productId
    type: UUID
    required: true
    description: Identifier for the product being ordered
    references: Product
    referencesIdentifier: productId
    relationType: hasOne 
  - name: productName
    type: string
    required: false # Often denormalized for performance/display
    description: Name of the product at the time of order
  - name: quantity
    type: integer
    required: true
    description: Number of units of the product ordered
  - name: unitPrice
    type: decimal
    required: true
    description: Price per unit of the product at the time of order
  - name: totalPrice
    type: decimal
    required: true
    description: Total price for this item line (quantity * unitPrice)
---

## Overview

The OrderItem entity details a specific product and its quantity requested within an `Order`. It holds information about the product, the quantity ordered, and the price calculation for that line item. OrderItems are part of the `Order` aggregate.

### Entity Properties
<EntityPropertiesTable />

## Relationships

*   **Order:** Each `OrderItem` belongs to exactly one `Order` (identified by `orderId`). It is a constituent part of the Order aggregate.
*   **Product:** Each `OrderItem` refers to one `Product` (identified by `productId`).

## Examples

*   **OrderItem A (for Order #12345):** Product ID: P001, Quantity: 2, Unit Price: $50.00, Total Price: $100.00
*   **OrderItem B (for Order #12345):** Product ID: P002, Quantity: 1, Unit Price: $75.00, Total Price: $75.00
